Slider tester and method for testing slider

ABSTRACT

A slider tester includes a disk, movable table, table drive mechanism, guide member, etc. A plurality of suspensions are mounted on the movable table. A slider is mounted on each suspension. A guide member can support respective lift tabs of the suspensions. The guide member includes a first guide surface, second guide surface, and opening arranged in a track width direction of the disk. When any of the lift tabs gets into the opening as the movable table moves in the track width direction of the disk, the slider is dropped toward a recording surface of the disk.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromprior Japanese Patent Application No. 2008-117774, filed Apr. 28, 2008,the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a slider tester for inspecting a slider of adisk drive used in an information processing apparatus or the like.

2. Description of the Related Art

A hard disk drive (HDD) includes a disk that functions as a recordingmedium, disk drive suspension (hereinafter simply referred to as thesuspension), actuator arm on which the suspension is mounted, etc. Datais magnetically recorded on the disk. A slider is mounted on the distalend portion of the suspension. This slider is provided with amagnetoelectric element used to access data to a recording surface ofthe disk, that is, an element for writing or reading data.

The suspension includes a base plate fixed to the actuator arm, loadbeam attached to the base plate, flexure located along the load beam,etc. The slider is mounted on a tongue (gimbal portion) formed on theflexure. When the disk is rotated at high speed by a spindle motor, theslider is caused to fly slightly above the surface of the disk by airthat flows between the disk and slider, thereby forming an air bearingbetween the disk and slider. The flying height of the slider is keptwithin an appropriate range.

Before the suspension is incorporated into an actual disk drive, theslider is checked for acceptability by means of a slider tester. Anexample of a conventional slider tester is disclosed in Jpn. Pat. Appln.KOKAI Publication No. 2004-86976 (Patent Document 1). In this slidertester, a slider is fixed to an arm portion so as to share the sameconditions with an actual suspension. A magnetic disk is rotated so thatthe slider flies, and the properties of the slider are measured.

On the other hand, a slider tester (slider supporting device) disclosedin Jpn. Pat. Appln. KOKAI Publication No. 2005-322377 (Patent Document2) includes dummy load beams, flexures, etc., constructed in the samemanner as those of actual suspensions. This slider tester is configuredso that a slider can be removably attached thereto. In the slidertester, a disk is rotated with the slider mounted on a suspension, andvarious inspections are conducted with the slider flying above thesurface of the disk. Any slider judged to be unacceptable by theseinspections is rejected.

Only one slider can be mounted in each of the slider testers describedin Patent Documents 1 and 2. The properties of the slider are measuredby accessing the recording surface of the disk with a magnetoelectricelement of the slider after the slider is moved to a predeterminedposition above the disk. After the measurement, the slider is moved toits original position and removed from the tester. Conventionally,therefore, each slider is singly mounted in the tester as it is tested.Thus, testing a plurality of sliders is not efficient and requires along time.

In order to improve the efficiency of the slider inspection operation,an attempt was made to provide a common table with a plurality ofsuspensions for a tester each mounted with a slider. A plurality ofsliders simultaneously move to a region above the recording surface ofthe disk as the table is moved radially relative to the disk (or alongthe track width). However, the peripheral rotational speed of the diskvaries considerably between the inner and outer peripheral sides. Theflying height of the slider depends on the peripheral rotational speedof the disk. Thus, the flying height of the slider that is moved to, forexample, the inner peripheral portion of the disk tends to becomesmaller than when the slider is at the outer peripheral portion.

If conducting a read/write test for the slider using the radial centralpart of the disk, the flying height is adjusted to an appropriate valuebased on the radial intermediate part. If the slider moves to the innerperipheral side of the disk, therefore, its flying height becomessmaller than the appropriate value. In consequence, the slider mayinterfere with the recording surface of the disk.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a slider tester capable of safely andefficiently testing a plurality of sliders used in a disk drive.

The invention is a slider tester for inspecting a slider for a diskdrive, which comprises: a disk for use as a recording medium; arotational mechanism which rotates the disk; a suspension including alift tab on the distal end thereof and a gimbal portion on which theslider is mounted; a movable table movable in a track width direction ofthe disk; a table drive mechanism which moves the movable table in thetrack width direction; a signal processing section which is electricallyconnected to an element of the slider and processes a signal to access arecording surface of the disk; and a guide member which is locatedbetween the lift tab and the recording surface of the disk and supportsthe lift tab, thereby preventing the slider from falling onto the disk.The movable table includes a suspension support portion which holds aplurality of the suspensions arranged in the track width direction ofthe disk. The guide member includes a guide surface extending in therack width direction of the disk and in contact with the lift tab and anopening which is formed in the middle with respect to the track widthdirection of the guide surface and allows the lift tab to move towardthe recording surface of the disk.

In this slider tester, the movable table is moved along the track widthof the disk so that the respective lift tabs of the suspensions, eachhaving the slider thereon, are situated one after another in the openingof the guide member, and the sliders are successively dropped toward therecording surface of the disk. By doing this, the sliders can beinspected in succession and tested efficiency. According to the slidertester of the invention, only the slider being inspected, out of thesliders mounted on the movable table, can be opposed to the recordingsurface of the disk. The other sliders can be kept on standby inpositions distant from the recording surface of the disk with the lifttabs supported by the guide member.

In a preferred aspect of the invention, the guide member includes afirst guide surface, which is inclined so that a distance from therecording surface of the disk gradually decreases from the outerperipheral side of the disk toward the opening, and a second guidesurface, which is inclined so that a distance from the recording surfaceof the disk gradually increases from the opening toward the innerperipheral side of the disk.

Further, the suspension may be provided with a clamp mechanism whichremovably holds the slider, the clamp mechanism including a firstsupport portion which supports one end portion of the slider, a secondsupport portion which supports the other end portion of the slider, anda spring portion which urges the second support portion toward the firstsupport portion with the slider interposed between the first and secondsupport portions.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention.

FIG. 1 is a partial plan view of a slider tester according to anembodiment of the invention;

FIG. 2 is a perspective view of a suspension used in the slider testershown in FIG. 1;

FIG. 3 is a plan view showing a movable table of the slider tester in astandby position;

FIG. 4 is a plan view showing a state in which a lift tab of a firstsuspension mounted on the movable table is situated in an opening of aguide member;

FIG. 5 is a plan view showing a state in which a lift tab of a thirdsuspension mounted on the movable table is situated in the opening ofthe guide member;

FIG. 6 is a front view showing a state in which the lift tab of thefirst suspension is moving toward the opening of the guide member;

FIG. 7 is a front view showing a state in which the lift tab of thefirst suspension is in the opening of the guide member;

FIG. 8 is a front view showing a state in which the lift tab of thefirst suspension is on a second guide surface; and

FIG. 9 is a front view showing a state in which a lift tab of a secondsuspension is in the opening of the guide member.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the present invention will now be described withreference to FIGS. 1 to 9.

A slider tester 10 shown in FIG. 1 includes a disk 11 that functions asa recording medium, movable table 12, table drive mechanism 13, guidemember 14, signal processing section 15, etc. The disk 11 has arecording surface 11 a on which data can be magnetically recorded. Thedisk 11 is rotated in a fixed direction (indicated by arrow A in FIG. 1)by a rotational mechanism 17 with a spindle 16.

The movable table 12 can reciorocate transversely along guide members 18relative to the track of the recording surface 11 a of the disk 11 (orin the direction indicated by arrow B in FIG. 1). An example of thetable drive mechanism 13 includes a servomotor 20 and ball screw 21. Asthe servomotor 20 rotates, the movable table 12 can move for a desireddistance along the track width. The signal processing section 15 thatfunctions as a controller can control the table drive mechanism 13 byusing an information processing apparatus, such as a personal computer.

The movable table 12 is provided with a suspension support portion 25.Suspensions 30A to 30C for the slider tester 10 are located on thesupport portion 25. These suspensions are arranged transversely relativeto the track of the disk 11 (or in the direction indicated by arrow B inFIG. 1) in parallel relation. The suspensions 30A to 30C have the sameconfiguration.

FIG. 2 shows an example of the suspension 30A for the slider tester. Thesuspension 30A is constructed in substantially the same manner asuspension that is incorporated in an actual hard disk drive.Specifically, the suspension 30A is provided with a base portion 32including a base plate 31, load beam 33 attached to the base plate 31,and flexure 34 located along the load beam 33. Springy hinge portions 35are disposed between the base portion 32 and load beam 33. The hingeportions 35 can bend along the thickness of the load beam 33.

A load/unload tab, that is, a lift tab 40 formed of a projection, isdisposed on the distal end of the load beam 33. The lift tab 40 extendsalong an axis X of the load beam 33. The tab 40 protrudes forward fromthe distal end of the load beam 33.

A gimbal portion 45 is provided near the distal end portion of theflexure 34. The gimbal portion 45 includes a tongue 51 on which a slider50 is mounted and a clamp mechanism 52 for fixing the slider 50. Theclamp mechanism 52 is composed of a first support portion 53, secondsupport portion 54, a pair of spring portions 55, etc. The first supportportion 53 is in contact with one end portion 50 a of the slider 50. Thesecond support portion 54 is in contact with the other end portion 50 bof the slider 50. The pair of spring portions 55 connect the supportportions 53 and 54 to each other. The slider 50 is interposed betweenthe first and second support portions 53 and 54. In this state, thesecond support portion 54 is urged toward the first support portion 53by the spring portions 55.

The spring portions 55 are formed individually on the opposite sides ofthe gimbal portion 45 by etching a part of the flexure 34 that is formedof a metal plate. An example of each spring portion 55 is a flat springhaving U-shaped convexes and inverted-U-shaped concaves. These convexesand concaves are alternately formed along the axis of the flexure 34,that is, along the axis X of the load beam 33.

Read/write elements, that is, magnetoelectric elements 60 are disposedon the end portion 50 a of the slider 50 that constitutes a magnetichead. The elements 60 are transducers such as magnetoelectric devices,which are used to access data to the recording surface 11 a of the disk11. The elements 60 electrically conduct to a terminal area 61 of theslider 50.

The flexure 34 is provided with a circuit member 65. When the slider 50is clamped by the clamp mechanism 52, the terminal area 61 of the slider50 electrically conducts to the circuit member 65. The circuit member 65is connected to the signal processing section 15 (shown in FIG. 1). Thesignal processing section 15 accesses (writes or reads) data to or fromthe recording surface 11 a of the disk 11 through the elements 60.

The guide member 14 is mounted on a frame 69 (partially shown in FIG. 1)of the slider tester 10 and can stand still with respect to the disk 11.The guide member 14 is formed of a self-lubricating synthetic resin,such as polyacetal, and is located between the recording surface 11 a ofthe disk 11 and the lift tabs 40.

The guide member 14 has a guide surface 70 that supports the lift tab40. The guide surface 70 extends transversely relative to the track ofthe disk 11 (or in the direction indicated by arrow B in FIG. 1).Further, the guide member 14 has a first guide surface 71, second guidesurface 72, and opening 73, which are arranged transversely relative tothe track of the recording surface 11 a. The opening 73 is formedbetween the first and second guide surfaces 71 and 72. The opening 73 issufficiently large to allow the passage of each lift Lab 40 along thethickness of the guide member 14 toward the recording surface 11 a ofthe disk 11.

As shown in FIG. 6, the guide member 14 is located at a certain distanceH from the recording surface 11 a of the disk 11. The first guidesurface 71 is inclined so that a distance h1 from the recording surface11 a of the disk 11 gradually decreases from the outer peripheral sideof the disk 11 toward the opening 73. The second guide surface 72 isinclined so that a distance h2 from the recording surface 11 a of thedisk 11 gradually increases from the opening 73 toward the innerperipheral side of the disk 11.

The distance from the recording surface 11 a of the disk 11 to each lifttab 40 is equivalent to the height of the tab 40. The height of the lifttab 40 is such a height that the tab 40 in the opening 73 can get on thefirst or second guide surface 71 or 72 when it moves transverselyrelative to the track.

The following is a description of the operation of the slider tester 10according to the present embodiment.

FIG. 3 shows the movable table 12 moved to a standby position. In thisstandby position, the table 12 is kept radially apart from the outerperipheral portion of the disk 11. The respective base portions 32 ofthe suspensions 30A to 30C are fixed to the suspension support portion25 of the movable table 12. The slider 50 is held on the gimbal portion45 of each of these suspensions by the clamp mechanism 52.

As the movable table 12 moves in the direction indicated by arrow B1from the standby position shown in FIG. 3, the suspensions 30A to 30Cindividually move transversely relative to the track toward the innerperipheral portion of the disk 11. As partially shown in FIG. 6, therespective lift tabs 40 of the suspensions 30A to 30C move transverselyrelative to the track (or in the direction indicated by arrow B1) asthey slide on the guide surface 70 of the guide member 14.

When the movable table 12 moves transversely relative to the track, asshown in FIGS. 4 and 7, the lift tab 40 of the suspension 30A in aleading position with respect to the movement reaches the opening 73,guided by the first guide surface 71. As the tab 40 gets into theopening 73, the slider 50 of the first suspension 30A is dropped towardthe recording surface 11 a of the disk 11.

Since the disk 11 rotates at high speed, air flows between the recordingsurface 11 a and slider 50 above it, thereby forming an air bearingbetween the slider and recording surface. Thus, the slider 50 flies atan appropriate flying height above the recording surface 11 a of thedisk 11.

When the slider 50 is thus situated above the recording surface 11 a,the movable table 12 is temporarily stopped as required, and data isaccessed to or from the recording surface 11 a of the disk 11 throughthe elements 60. The data is written to the recording surface 11 a ofthe disk 11 through the elements 60, based on, for example, a writecurrent output from the signal processing section 15. Alternatively,data recorded on the recording surface 11 a is read by means of theelements 60 and output to the signal processing section 15. The slider50 is inspected based on these data.

After the slider 50 of the first suspension 30A is inspected, themovable table 12 is further moved transversely relative to the track (orin the direction indicated by arrow B1 in FIG. 4). Thereupon, the lifttab 40 of the suspension 30A gets on the second guide surface 72, asshown in FIG. 8, and then moves toward the inner peripheral portion ofthe disk 11. Thus, the slider 50 is kept apart from the recordingsurface 11 a of the disk 11 and held by the guide member 14.

As shown in FIGS. 1 and 9, the lift tab 40 of the second suspension 30Breaches the opening 73. As the tab 40 of the second suspension 30B getsinto the opening 73, the slider 50 is dropped toward the recordingsurface 11 a of the disk 11. After the second slider 50 is tested, themovable table 12 is further moved transversely relative to the track.

As shown in FIG. 5, the lift tab 40 of the third suspension 30C reachesthe opening 73. As the tab 40 of the third suspension 30C gets into theopening 73, the slider 50 is dropped toward the recording surface 11 aof the disk 11.

After the inspections of the respective sliders 50 of the suspensions30A to 30C are finished, the movable table 12 is returned to a standbyposition shown in FIG. 1. In this standby position, the distance betweenthe support portions 53 and 54 of each clamp mechanism 52 is increasedby using a removal jig (not shown). By doing this, each slider 50 isremoved from the gimbal portion 45. Any of the sliders 50 judged to beacceptable by the inspection is attached to its corresponding suspensionincorporated in the actual disk drive. Any slider judged to beunacceptable by the inspection is rejected.

As described above, the plurality of sliders 50 can be successivelyinspected as the movable table 12 on which the suspensions 30A to 30Care mounted is moved transversely relative to the track of the recordingsurface 11 a. Thus, the sliders 50 can be efficiently inspected in ashort time.

In the slider tester 10 of the present embodiment, the slider 50 of thatsuspension which, among the suspensions 30A to 30C held on the movabletable 12, has its lift tab 40 in the opening 73 is opposed to therecording surface 11 a of the disk 11 and inspected. The sliders 50 notbeing inspected are left on standby in positions apart from the disk 11without being dropped onto the disk.

Without the guide member 14, the flying height of the slider 50 movedclose to the inner peripheral portion of the disk 11 may be smaller thanan appropriate value, owing to variations in workmanship between thesuspensions, restrictions on the accuracy of the movable table 12, etc.If the flying height is smaller than the appropriate value, the slider50 may contact the disk 11.

According to the present embodiment, however, only the slider 50 beinginspected can be made to fly at the appropriate flying height above therecording surface 11 a of the disk 11. The other sliders 50 can be kepton standby in positions sufficiently distant from the recording surface11 a of the disk 11 by the guide member 14. For example, therefore, theslider 50 that is on standby in a position near the inner peripheralportion of the disk 11 can be prevented from contacting the recordingsurface 11 a of the disk 11, so that the inspection can be conductedsafely.

In the embodiment described herein, the dummy suspensions 30A to 30Cdedicated for the tester are mounted on the suspension support portion25 of the movable table 12. For another embodiment, however, a pluralityof head-gimbal assemblies (HGAs) incorporated in the actual hard diskdrive may be mounted on the suspension support portion 25 of the movabletable 12. Since each HGA includes a suspension and slider, therespective sliders of the HGAs can be efficiently inspected by using theslider tester 10. The number of suspensions mounted on the suspensionsupport portion 25 of the movable table 12 may also be any number otherthan three.

It is to be understood, in carrying out the invention, that thecomponents of the slider tester, including the disk, movable table,table drive mechanism, guide member, and suspensions, may be modifiedvariously without departing from the scope of the invention.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

1. A slider tester for inspecting a slider for a disk drive, comprising:a disk for use as a recording medium; a rotational mechanism whichrotates the disk; a suspension including a lift tab on the distal endthereof and a gimbal portion on which the slider is mounted; a movabletable movable in a track width direction of the disk; a table drivemechanism which moves the movable table in the track width direction; asignal processing section which is electrically connected to an elementof the slider and processes a signal to access a recording surface ofthe disk; and a guide member which is located between the lift tab andthe recording surface of the disk and supports the lift tab, therebypreventing the slider from falling onto the disk, the movable tableincluding a suspension support portion which holds a plurality of saidsuspensions arranged in the track width direction of the disk, the guidemember including a guide surface extending in the track width directionof the disk and in contact with the lift tab and an opening which isformed in the middle with respect to the track width direction of theguide surface and allows the lift tab to move toward the recordingsurface of the disk.
 2. The slider tester according to claim 1, whereinthe guide member includes a first guide surface, which is inclined sothat a distance from the recording surface of the disk graduallydecreases from the outer peripheral side of the disk toward the opening,and a second guide surface, which is inclined so that a distance fromthe recording surface of the disk gradually increases from the openingtoward the inner peripheral side of the disk.
 3. The slider testeraccording to claim 1, wherein the suspension is provided with a clampmechanism which removably holds the slider, the clamp mechanismincluding a first support portion which supports one end portion of theslider, a second support portion which supports the other end portion ofthe slider, and a spring portion which urges the second support portiontoward the first support portion with the slider interposed between thefirst and second support portions.
 4. The slider tester according toclaim 2, wherein the suspension is provided with a clamp mechanism whichremovably holds the slider, the clamp mechanism including a firstsupport portion which supports one end portion of the slider, a secondsupport portion which supports the other end portion of the slider, anda spring portion which urges the second support portion toward the firstsupport portion with the slider interposed between the first and secondsupport portions.